I was pressure testing my manifold and found air escaping through the chain oiler. I have it closed off for a belt drive so Im confused on why I'm getting a steady flow of air. I think it could be a leaking valve or rings but I don't want to believe that since I just had a top end rebuild 1500 miles ago and it runs good. What am I missing?
Thanks,
Steve
Manifold Pressure test
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jank1331
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RUBONE
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Re: Manifold Pressure test
Despite the chain oiler being "closed off", that merely stops the pump from supplying oil, it is still the escape route for crankcase pressure. And it is going past rings or valves if it is leaking from the port. Or it is leaking through the head into the rocker box area. Are you sure both your intake valves were completely closed for the test? They are not both closed for much crank rotation. The best way to do it is to remove the intake pushrods, or at least loosen them so the valves are closed! Any air into the cases or top end will come out the breather/oiler tube!
Robbie
Robbie
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Cotten
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Re: Manifold Pressure test
Just for reference Folks,
Indians' intakes seem to never be shut at the same time.
Yet collapsing the valve train is un-necessary, as your regulator should keep up the pressure differential.
As Robbie points out, opening the valves, and listening to other places on the motor can certainly give clues to other concerns, such as a burnt exhaust valve heard through the exhaust.
Soapy water around the headgaskets can be a heartbreak.
But it is better than not knowing.
....Cotten
Indians' intakes seem to never be shut at the same time.
Yet collapsing the valve train is un-necessary, as your regulator should keep up the pressure differential.
As Robbie points out, opening the valves, and listening to other places on the motor can certainly give clues to other concerns, such as a burnt exhaust valve heard through the exhaust.
Soapy water around the headgaskets can be a heartbreak.
But it is better than not knowing.
....Cotten
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jank1331
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Re: Manifold Pressure test
I did check everything else with soapy water: manifold, head gasket, spark plugs, valve cover screw holes and everything else is sealed. The pressure is maintained in the rest of the system except for the oiler- no audible leaks anywhere else. I will try it again to see if rotation the engine will help to find a "sweet" spot.
Thanks for the replies,
Steve
Thanks for the replies,
Steve
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SeaHag
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Re: Manifold Pressure test
The only thing I can think of in the intake is the valve guides. 1500 miles ago? Could they be worn already? The only thing in there that could lead to the crankcase pressure, thru to the heads then thru oil drain thru cylinders to case?